It is common, in manufacturing facilities, to find automated processes controlled by low level automation and process control and monitoring systems. Low level automation systems may include, for example, dedicated robotic devices or other automated systems controlled or monitored by programmable logic controllers (PLC's). Various sensing devices and instrumentation may also be used to monitor the processes, such as photo eyes, barcode readers and temperature sensors. To manage the plethora of complex manufacturing and assembly systems used today, many enterprises use a multi-tiered architecture, such as the prior art example shown in FIG. 1. A conventional multi-tiered architecture may include: enterprise level business planning systems (enterprise resource planning, or ERP) 102; operations level (manufacturing execution systems, or MES) 104; mid-level process optimization systems 106 (e.g. human machine interface (HMI), supervisory control and data acquisition (SCADA), viewable plant floor status, data collection for upstream reporting); and low level process automation or controls systems 108, including sensors or other instrumentation 110.
Many customers may find that the number of systems necessary to implement the mid-level control systems 106 makes installation and maintenance too difficult. Mid-level control systems 106 are often either too complex, for example mini manufacturing resource planning (MRP) systems for scheduling, or too simple and limited in functionality, for example SCADA/HMI data status only. Also, there is typically a division of responsibility for standard computer information technology (IT) equipment between an IT support group and a plant floor support group.
It is often desirable to have the ability, at ERP level 102, to have direct access to information currently available only on the plant floor, for example, sensor readings or number of units produced. The major roadblock in attaining direct connection between the enterprise level systems and the plant floor devices has been non-standard communication protocols inherent in devices used on the plant floor. The standard communication mechanisms at the enterprise level 102 (e.g. message queues) are different from the standard communication mechanisms at the low level manufacturing device levels 108, 110 (e.g. DeviceNet and other proprietary protocols). Additionally, the number of layers between ERP level 102 and controls and sensors 108 and 110 respectively tends to make direct communication between those levels difficult.
Therefore, it would be desirable to have a means of direct communication between low level control and sensing levels 108 and 110 and the enterprise level 102 both for the acquisition of data direct from the manufacturing floor and the ability to control manufacturing processes directly.